Cytomegalovirus (CMV) infection is the most common viral infection after haematopoietic stem cell transplantation (HSCT). However, studies on related risk factors give different views without any clear conclusion. Therefore, the purpose of this study was to evaluate the risk variables of CMV infection after HSCT in order to provide recommendations for therapeutic treatment. The National Knowledge Infrastructure [CNKI], Chinese Biomedical Literature database [SinoMed], Wanfang Digital Periodicals [WANFANG] and China Science and Technology Journal [VIP] databases, as well as PubMed, Embase, CENTRAL, Web of Science databases were searched. The search keyword was Cumulative Index of Nursing and Related Health Literature (CINAHL). The search time spanned from the time when the database was created to February 2023. Based on inclusion and exclusion criteria, two researchers independently chose the literature, retrieved data, and assessed the bias risk. The methodological quality of the included studies was assessed by the Newcastle Ottawa scale (NOS). A total of 1,038 literatures were retrieved, of which, 18 studies were finally included. The final results of meta-analysis showed that there were seven risk factors as follows: Acute graft-versus-host disease (aGVHD) grades II-IV (II-IV) [odds ratio = 3.39, 95% CI (2.13, 5.41), p <0.05]; ant-thymocyte globulin (ATG) administration in treatment [odds ratio = 2.53, 95% CI (1.41, 4.53), p <0.05]; cyclosporine level after transplantation (>300 ng/ml) [OR = 3.79, 95% CI (1.24, 11.65), p <0.05]; age [odds ratio = 1.83, 95% CI (1.06, 3.15), p <0.05]; neutrophil deficiency time [odds ratio = 6.58, 95% CI (2.24, 19.30), p <0.05]; CMV infection in recipients before transplantation [odds ratio = 6.32,95% CI (4.03, 9.90), p <0.05]; fungal infection [odds ratio = 2.63, 95% CI (1.09, 6.34), p <0.05]. This study preliminarily revealed that CMV infection after HSCT is related to aGVHD (II-IV), ATG administration in pretreatment, cyclosporine level (>300 ng/ml) after transplantation, age, neutrophil deficiency time, CMV infection in recipients before transplantation and fungal infection. However, the mechanisms behind the risk variables are unclear. Further research is necessary to understand the risk factors and to enhance the care of patients with these risk factors to prevent or control infection. Key Words: Haematopoietic stem cell transplantation, Cytomegalovirus infection, Risk factors, Meta-analysis.